Clinical Prognosis of Optimal Medical Therapy After Percutaneous Coronary Intervention in Patients with Coronary Heart Disease
Coronary heart disease (CHD) remains a leading cause of morbidity and mortality worldwide. Revascularization, whether through percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG), is the dominant treatment for severe CHD. However, the long-term clinical outcomes of revascularization are unpredictable due to the progression of atherosclerosis that continues after surgery. Optimal medical therapy (OMT) has been proven to be critical in reducing the incidence of adverse events and improving the quality of life in patients with CHD, both with and without revascularization. In recent years, studies from China have shown that patients with higher adherence to medical therapy have a lower incidence of adverse events at one year after PCI. Despite this, there has been a lack of large clinical trials or observational studies in China to accurately understand the maintenance of medical strategies in patients with CHD. This study aimed to investigate the use of OMT and evaluate its association with clinical prognosis after PCI.
The study prospectively collected data from patients with CHD who underwent PCI at the TEDA International Cardiovascular Hospital between October 2016 and September 2017. The study was approved by the Institutional Ethics Board of the hospital, and due to its retrospective nature, the requirement for written informed consent was waived. Participants were included if they were treated with standard PCI following the Chinese PCI Guidelines (2016) after a coronary angiography examination. All patients were followed up after discharge either via an outpatient service or via telephone when the service was not feasible. Exclusion criteria included contraindications or intolerance to specified drugs of OMT, tumor or less than one-year life expectancy, immune system disease, the presence of renal failure found during hospitalization, incomplete clinical or coronary angiography records, and death before discharge. Demographic and clinical characteristics of the patients were obtained from the hospital database, including age, sex, body mass index (BMI), highest degree, payment method, tobacco use, diagnosis, and complications of CHD.
OMT was defined as a combination of dual antiplatelet therapy (DAPT) (aspirin and a P2Y12 antagonist), statins, beta-blockers, and angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). The clinical endpoint of the study was major adverse cardiovascular events (MACE), which comprised all-cause mortality, hospitalization for non-fatal myocardial infarction (MI), and stroke. The follow-up lasted one year after discharge unless the endpoint was observed.
Categorical variables were described as counts with percentages, and continuous variables were expressed as mean ± standard deviation. Differences between groups (OMT and non-OMT groups) were analyzed using the Pearson chi-square test for categorical variables and the two independent samples t-test for continuous variables. To examine the effect of using OMT and each individual agent on the risk of the endpoint after PCI, unadjusted and adjusted hazard ratios (HRs) from Cox proportional hazards models were established. Four covariate models were used for each specific medication class, adjusted for age, BMI, a history of MI, PCI, and heart failure (HF), the number of coronary artery lesions, the medication status for each agent at hospitalization, and the use of the other three classes of drugs at one year after discharge. Another model for OMT was adjusted for age, BMI, a history of MI, PCI, and HF, the number of coronary artery lesions, and OMT at hospitalization. Each variable identified with univariate analysis or previous clinical consideration was selected for inclusion in the adjusted multivariate models. All data were analyzed using IBM SPSS version 22.0, with two-tailed statistics and a significance level of P < 0.050.
A total of 3812 patients were recruited after completing PCI, with 224 patients excluded (154 refused follow-up, and contact information was lost for 70). The final cohort consisted of 3588 patients at the end of follow-up, of whom 1299 (36.2%) persisted with OMT. Two-thirds of the patients in this cohort had more than one comorbidity of CHD, including hypertension, diabetes, hyperlipidemia, and tobacco use. Patients in the OMT group who received OMT at one year after discharge were more likely to have a college degree, medical insurance of employees, more coronary lesions, and a history of PCI compared with those in the non-OMT group.
At hospitalization, 58.8% (2108/3588) of patients received OMT, and the rates of DAPT, statins, beta-blockers, and ACEIs/ARBs were 99.6% (3575/3588), 96.2% (3452/3588), 75.3% (2701/3588), and 75.0% (2692/3588) at baseline, respectively. At the one-year follow-up, the treatment rate of DAPT and statins remained high (>85.0%), but the use of beta-blockers was reduced to less than 60.0%, and that of ACEIs or ARBs decreased by almost 30%. The use of beta-blockers and ACEIs or ARBs showed a dramatic downward trend. At the end of the follow-up, only 36.2% of patients received OMT, which comprised all four classes of medications.
Table 1 shows the associations between MACE at one year after PCI and the use of OMT or each individual agent. Each class of OMT was associated with a significant reduction in MACE at one year, with a remarkable effect observed using DAPT due to its higher rate of medication use (HR = 0.122, 95% CI: 0.078–0.191, P < 0.001). The use of statins (HR = 0.435, 95% CI: 0.279–0.677, P < 0.001), beta-blockers (HR = 0.614, 95% CI: 0.387–0.972, P < 0.038), ACEIs/ARBs (HR = 0.433, 95% CI: 0.281–0.667, P < 0.001), and OMT (HR = 0.382, 95% CI: 0.244–0.599, P < 0.001) were also significantly associated with a decrease in adverse events.
The benefits of statins and DAPT have been recognized in recent years, with DAPT improving clinical outcomes compared with aspirin alone in patients with acute coronary syndrome. The use of beta-blockers after acute coronary syndrome is indicated in clinical practice unless patients have severe complications and is associated with a 30% lower rate of mortality or non-fatal MI. Similarly, the use of ACEIs or ARBs is recommended in patients undergoing acute coronary syndrome with HF or left-ventricular dysfunction. However, data on the advantage of OMT remain limited. In this study, the use of each individual agent was associated with a reduction in adverse events. However, OMT, which was a combination of DAPT, statins, beta-blockers, and ACEIs/ARBs, showed better improvement of long-term outcomes compared with each agent alone.
The medication status in the long term remained suboptimal. The SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery (SYNTAX) trial showed that the proportion of patients who received OMT was only 41.3% at discharge after revascularization (PCI, 50.2% vs. CABG, 31.2%) and nearly one-third at the five-year follow-up (PCI, 39.6% vs. CABG, 35.7%). Additionally, OMT was correlated with a remarkably lower hazard of death and the composite endpoint (death, MI, and stroke) in five years. Therefore, essential measures should be taken to improve adherence to OMT in patients receiving revascularization surgically or interventionally.
OMT in this study played a crucial role in treating patients after PCI and should be recommended to all patients with complications. This recommendation is also supported by an analysis of almost 3000 patients after revascularization in the Project of Ex-vivo Vein Graft Engineering via Transfection (PREVENT) IV trial. This trial showed that composite medication use, but not each individual agent (antiplatelets, beta-blockers, ACEIs/ARBs, or lipid-lowering therapy), reduced the incidence of mortality or MI at a two-year follow-up. However, a randomized clinical trial also showed that not all patients with newly diagnosed CHD benefited from beta-blocker therapy. This previous finding suggests that the advice may not be appropriate for patients with only a few comorbidities, and more population-based research is required to investigate the effect of OMT on these patients.
The study has some limitations. It was a monocentric, observational study in China, and therefore, the generalizability of the findings should be treated carefully. The use of drugs evaluated by patients’ answers during the follow-up may not be reflective of their actual medication status. Moreover, specific reasons for the interception of OMT in the long term, including intolerance or contraindication of medication, and non-adherence in patients and physicians, were not recorded.
In conclusion, the use of OMT in patients with CHD undergoing PCI remains suboptimal. Adherence to OMT (DAPT, statins, beta-blockers, and ACEIs/ARBs) is associated with a lower incidence of adverse cardiovascular events, including all-cause death, non-fatal MI, and stroke. OMT should be suggested to patients with CHD, especially those with comorbidities.
doi.org/10.1097/CM9.0000000000001720
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